Bill Nye: Deflecting Asteroids Is Hard, But Not <em>That</em> Hard

America's favorite bow-tied Science Guy writes off Mars colonization, explains the science behind asteroid detection, and describes how researchers are working to ensure we don't go the way of the dinosaurs.

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PCMag: It sounds like we are making advances in our abilities to detect asteroids. Where are we in our abilities to deflect asteroids? It sounds much harder.

Bill Nye: Actually, when you talk to certain people, they'll say it's hard but it's not that hard. The whole thing is about finding them in time. And when I say time, I'm talking 10 years, 20 years. Then, if you could characterize it and know what it is made [from] well enough, and you determine that it is solid, you could just smash into it with another spacecraft. If the thing is going 20 kilometers per secondper second!relative to the Earth, you need to change its speed about two millimeters per second. So you're talking on the order of 10-7. You're talking about a hundred-thousandth of a percent in velocity change. You don't have to blow it upyou don't have to go Bruce Willis on the thing. You want to just nudge it so that it crosses the Earth's orbit at a different time. It's a really cool idea. But if you don't detect it in time, it's very difficult to do anything.

There's another very cool idea, one that former NASA astronaut Ed Lu got a patent on, to send out a spacecraft so massivehow massive would it be?so massive that its gravity would tug the object off course just slightly.

PCMag: Wow. Do we have the capabilities to build something so big?

Bill Nye: So this is an argument for the Asteroid Redirect Mission. It would be the first time anybody ever built a solar electric propulsion motor big enough to deflect an object. We have 5-kilowatt gizmos, now they want to make 50-kilowatts. Ten times as big. An Asteroid Redirect Missionit used to be called an Asteroid Retrieval Missionwould take one-sixth of the world's annual production of xenon. That's a lot of xenon, and that's for making one that's a much smaller scale. So there might be a better fuel but the idea is pretty cool to just have a massive spacecraft and just nini-tiji-teetee-nudge it.

But as you may know, we at the Planetary Society are all kooky about the Laser Beesit's just the coolest idea. We're funding researchers at Strathclyde University in Glasgow, Scotland. So you get solar panels and you drive a big laser on a spacecraft, or a swarm of spacecrafts, like a swarm of bees. They direct their laser energy at the surface of the asteroid and the material that burns off, or ablates, or volatizes, or evaporates, has momentum and that momentum is enough to nudge the asteroid.

People thought that the dust or the ejecta would interfere with the laser beams so much that they wouldn't be effective, but the tests that the researchers in Scotland did this spring indicate there's not really that much of a problem. If the lasers are lasering properly, the ejecta go off in a different direction and don't mess up the beam. And these things would work together in essentially a cellphone network so they'd self-coordinate.

PCMag: How do you even test something like this?

Bill Nye: A big vacuum chamber with a great big laser. And a rock. A rock that's generally agreed to be asteroidal, or like an asteroid. It's cool! It's my favorite idea of all of them, I have to say. And it's funded by the Planetary Society which is about 30,000 going on 40,000 people around the world who just think this is cool. They send us money and it's not done by a government as such. It funds basic research into what sounds like an extraordinary science fiction ideabut it's a real idea and the tests indicate that it would really work.

PCMag: And lastly, what tech couldn't you do without?

Bill Nye: Couldn't do without? I certainly rely on a lot of technology; I rely on my laptop but "couldn't do without?" You're getting out there. I guess it would be my laptop.

But my irrigation system is pretty cool too. I mean, it works. It has a rain gauge and it monitors the daily rainfall and it waters the garden accordingly. I grow quite a bit of food in my gardenmore than I can eat right nowbut could I live without that? Ehhh.

I have a coffee milk foamer that makes milk foam perfectly. Perfectly. Not just the steamed one that goes "whhhiiirrr." It works in a different way and it's great. I use it all the time. Could I live without it? Yeah. Do I want to live without it? No!

Meredith Popolo joined the staff shortly after graduating from snowy Syracuse University, where she earned degrees in magazine journalism and entrepreneurship. So far, the highlight of her PCMag career has been covering the Mars Curiosity rover landing from NASA's JPL in Pasadena, California. When she's not writing about tech, tweeting about Syracuse basketball, or hunting Foursquare mayorships around New York, she's likely—wait, never mind, that's basically all she does.
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